The present invention relates to an auxiliary unit for plastics injection moulds for forming plastics articles having at least two components.
Currently it is known to produce moulded plastics articles having at least two components with different characteristics by the following method: initially one component, usually the main component having a predominant volume or weight, is formed in a pre-arranged main mould into which the one component is injected by means of plastics injection moulding machines.
On one side of the same mould there is moreover provided a connection by which an auxiliary injection unit for the separate injection of a second component can be positioned.
Currently it is known to couple the auxiliary injection unit to the main mould by means of a fixed coupling, that is by means of the use of pre-arranged fixing devices such as screws and bolts.
This arrangement has disadvantages in that the maintenance and/or replacement of the auxiliary unit involves rather long operating times and the necessity of using skilled personnel.
As a partial solution to avoid this disadvantage it is known to fit to the auxiliary unit a support which has a magnetic base allowing it to be associated with the mould.
This arrangement also, however, has disadvantages in that it involves additional production costs; moreover the positioning of the auxiliary unit must ensure its perfect alignment in correspondence with the connection on the main mould so as to allow optimum flow of material from the auxiliary unit to the mould; the achievement of this condition is not easy, requiring significant precision upon coupling of the auxiliary unit.
The main object of the present intention is therefore that of resolving the technical problem indicated by eliminating the disadvantages of the prior art and devising an auxiliary unit which can be easily and rapidly fitted to a main mould.
Within the scope of the above-explained object a further important object is that of providing an auxiliary unit in which the interconnection to the main mould also allows the achievement of a correct positioning for the injection of the second component of plastics material into the main mould without requiring the installer to exercise any precision in performing the coupling operation.
Another important object is that of providing an auxiliary unit which is easily removable for maintenance and/or replacement.
Not the least object is that of providing an auxiliary unit which is structurally simple whilst at the same time having low production costs.
The above-listed objects and functions, as well as others which will become more clearly apparent hereinafter, are achieved by an auxiliary injection unit for fitting to one side of a mould for forming articles of plastics material and including at least one connection for the injection of a further plastics material component, which is characterised in that the said unit has at one end a plate which can be fitted slidably to a slide formed in the said at least one connection.
Further characteristics and advantages will become apparent from the detailed description of a particular, but not exclusive, embodiment, illustrated by way of non-limitative example in the attached drawings, in which: